1. Field of the Invention
The invention relates to a circuit for performing the EXCLUSIVE-OR function of a signal A and B, which circuit comprises field effect transistors normally cut off in the absence of a gate-source signal and also comprises loads and is integrated on a semiconductor substrate, a signal A which is complementary to the signal A also being applied to this circuit.
The invention also relates to a circuit which performs the EXCLUSIVE-OR function of a signal A and a signal B and which generates the signals necessary for its operation.
The invention is used for the miniaturization of integrated circuits comprising logic gates of the EXCLUSIVE-OR type formed on a semiconductor substrate of a material of the group III-V, notably gallium arsenide.
2. Description of the Prior Art
An EXCLUSIVE-OR gate realized by means of field effect transistors of the MESFET type normally cut off in the absence of a gate-source signal on a gallium arsenide (Ga-As) substrate is known from a publication in "1986 IEEE gallium-arsenide integrated Circuit Symposium, Grenelefe, Fla., Oct. 28-30, 1986" entitled "A 0.1-4.5 GHz, 29 mW GaAs Prescaler operating at 125.degree. C." by Didier MEIGNANT, Etienne DELHAYE, Marc ROCCHI.
The circuit described in the cited publication comprises six field effect transistors and three loads for realizing the EXCLUSIVE-OR gate.
The required number of elements increases to eight transistors and five loads when also providing for the internal generation of a signal complementary to one of the input signals. This necessitates two supplementary inverter stages.